> > If you have the capability, is there any reason not to place the > > subscriber email address in the To: header of list messages, > > particularly announcement lists? > > You lose the ability for the MTA to group messages going to recipients > sharing the same domain inside a single envelope and deliver them together. > As a result it could take much longer to deliver messages and use more > bandwidth.
It turns out that individual deliveries take more bits but paradoxically are actually faster on all but the most overloaded networks due to the increased parallelism. That's not an important consideration unless you're running a huge list on a 28.8K modem which I hope nobody does any more. Nonetheless, I think that putting the individual recipient's address in the To: line is a pretty bad idea. Many PC mail programs have weak filtering features and can't filter on arbitrary headers, so without the list name in the To: header, they can't put mailing list mail in separate folders. I agree that looking for your own address in the To: and Cc: line isn't a bad spam heuristic, but if you're going to do that, you can put "whitelist" rules for your mailing list mail first. Regards, John Levine, [EMAIL PROTECTED], Primary Perpetrator of "The Internet for Dummies", Information Superhighwayman wanna-be, http://iecc.com/johnl, Sewer Commissioner Write for PGP key, f'print = 3A 5B D0 3F D9 A0 6A A4 2D AC 1E 9E A6 36 A3 47
